The thermal properties, in terms of the glass-transition, melting, and crystallization temperatures, were measured by differential scanning calorimetry analysis on the two high-molecular-weight PETs and, for comparison, on a bottle-grade GW4869 PET. The rheological properties were measured to asses the improvement of the high-molecular-weight PET with respect to the bottle-grade one.

Expansion tests were performed on the two high-molecular-weight grades and bottle-grade PETs with a batch foaming process with N(2), CO,, and an 80-20 wt %, N(2)-CO(2) mixture used as blowing agents. The whole processing window was explored in tern-is of temperature, pressure drop rate, and saturation pressure. The results of the foaming experiments were correlated to gas sorption and the thermal and rheological properties of the polymers in the molten state. The results proved the feasibility of foam processing these two high-molecular-weight grades, which gave, when compared 4SC-202 mouse to the bottle grade at specific foaming conditions, very low densities and fine morphologies. (C) 2009 Wiley Periodicals, Inc. J Appl

Polym Sci 116: 27-35, 2010″
“Maternal effects can play an important role in a diversity of ecological and evolutionary processes such as population dynamics, phenotypic plasticity, niche construction, life-history evolution and the evolutionary response to selection. However, although maternal effects were defined by quantitative geneticists well over half a century ago, there remains some confusion over exactly what phenomena should be characterized as maternal effects and, more importantly, why it matters and how they are defined. We suggest a definition of maternal effects as the causal influence of the maternal genotype or phenotype on the offspring phenotype. This definition differs from some definitions in that it treats maternal effects as a phenomenon,

not as a statistical construct. The causal link to maternal genotype or phenotype is the critical component of this definition providing the link between maternal effects and evolutionary and ecological processes. We show why phenomena such as maternal cytoplasmic inheritance click here and genomic imprinting are distinct genetically from and have different evolutionary consequences than true maternal effects. We also argue that one should consider cases where the maternal effect is conditional on offspring genotype as a class of maternal effects.”
“Study Design. Biomechanical analysis of derotational load-to-failure of pedicle screw (PS) instrumentation in cadaveric thoracic spinal segments.

Objective. To investigate the derotational torque that can be applied to the thoracic spine through different linked constructs and evaluate the modes of failure.

Summary of Background Data.